Time Measurements (time + measurement)

Distribution by Scientific Domains

Kinds of Time Measurements

  • photoperiodic time measurement
  • relaxation time measurement


  • Selected Abstracts


    Clock synchronization in Cell/B.E. traces

    CONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 14 2009
    M. Biberstein
    Abstract Cell/B.E. is a heterogeneous multicore processor that was designed for the efficient execution of parallel and vectorizable applications with high computation and memory requirements. The transition to multicores introduces the challenge of providing tools that help programmers tune the code running on these architectures. Tracing tools, in particular, often help locate performance problems related to thread and process communication. A major impediment to implementing tracing on Cell is the absence of a common clock that can be accessed at low cost from all cores. The OS clock is costly to access from the auxiliary cores and the hardware timers cannot be simultaneously set on all the cores. In this paper, we describe an offline trace analysis algorithm that assigns wall-clock time to trace records based on their thread-local time stamps and event order. Our experiments on several Cell SDK workloads show that the indeterminism in assigning wall-clock time to events is low, on average 20,40 clock ticks (translating into 1.4,2.8,µs on the system used in our experiments). We also show how various practical problems, such as the imprecision of time measurement, can be overcome. Copyright © 2009 John Wiley & Sons, Ltd. [source]


    THE CONTRIBUTION OF AN HOURGLASS TIMER TO THE EVOLUTION OF PHOTOPERIODIC RESPONSE IN THE PITCHER-PLANT MOSQUITO, WYEOMYIA SMITHII

    EVOLUTION, Issue 10 2003
    W. E. Bradshaw
    Abstract Photoperiodism, the ability to assess the length of day or night, enables a diverse array of plants, birds, mammals, and arthropods to organize their development and reproduction in concert with the changing seasons in temperate climatic zones. For more than 60 years, the mechanism controlling photoperiodic response has been debated. Photoperiodism may be a simple interval timer, that is, an hourglasslike mechanism that literally measures the length of day or night or, alternatively, may be an overt expression of an underlying circadian oscillator. Herein, we test experimentally whether the rhythmic response in Wyeomyia smithii indicates a causal, necessary relationship between circadian rhythmicity and the evolutionary modification of photoperiodic response over the climatic gradient of North America, or may be explained by a simple interval timer. We show that a day-interval timer is sufficient to predict the photoperiodic response of W. smithii over this broad geographic range and conclude that rhythmic responses observed in classical circadian-based experiments alone cannot be used to infer a causal role for circadian rhythmicity in the evolution of photoperiodic time measurement. More importantly, we argue that the pursuit of circadian rhyth-micity as the central mechanism that measures the duration of night or day has distracted researchers from consideration of the interval-timing processes that may actually be the target of natural selection linking internal photoperiodic time measurement to the external seasonal environment. [source]


    Measurement of informal care: an empirical study into the valid measurement of time spent on informal caregiving

    HEALTH ECONOMICS, Issue 5 2006
    Bernard van den Berg
    Abstract The incorporation of informal care into economic evaluations of health care is troublesome. The debate focuses on the valuation of time spent on informal caregiving, while time measurement, a related and may be even a more important issue, tends to be neglected. Valid time measurement is a necessary condition for the valuation of informal care. In this paper, two methods of time measurement are compared and evaluated: the diary, which is considered the gold standard, and the recall method, which is applied more often. The main objective of this comparison is to explore the validity of the measurement of time spent on providing informal care. In addition, this paper gives empirical evidence regarding the measurement of joint production and the separation between ,normal' housework and additional housework due to the care demands of the care recipients. Finally, the test,retest stability for the recall method is assessed. A total of 199 persons giving informal care to a heterogeneous population of care recipients completed the diary and the recall questionnaire. Corrected for joint production, informal caregivers spent almost 5.8 h a day on providing informal care. If one assumes that respondents take into account joint production when completing the recall questionnaire, the recall method is a valid instrument to measure time spent on providing informal care compared to the diary. Otherwise, the recall method is likely to overestimate the time spent on providing informal care. Moreover, the recall method proves to be unstable over time. This could be due to learning effects from completing a diary. Copyright © 2005 John Wiley & Sons, Ltd. [source]


    Characterizations of a Hot-Pressed Polycrystalline Spinel:Ce Scintillator

    JOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 8 2010
    Ching-Fong Chen
    Here, we report a new polycrystalline ceramic scintillator for possible use in ,-ray detection and medical imaging applications. The goal was to develop a cerium-doped spinel (MgAl2O4:Ce), which can be processed utilizing ceramic forming techniques. High-purity MgAl2O4 powders were used as the starting materials. Lithium fluoride (LiF) was used as a sintering aid and CeO2 powder was used as the dopant. The mixed and dried powders were hot pressed in a vacuum environment to achieve high-density MgAl2O4:Ce. The hot-pressed sample shows a transparent polycrystalline appearance. In-line transmission was measured to determine the transparency of the structure. Microstructures were characterized using X-ray diffraction and scanning electron microscopy. Fluorescence absorption and emission peaks were also measured in addition to the decay time measurement. [source]


    Diapause-inducing signals prolong nymphal development in the two-spotted spider mite Tetranychus urticae

    PHYSIOLOGICAL ENTOMOLOGY, Issue 3 2009
    TAKESHI SUZUKI
    Abstract Female two-spotted spider mite Tetranychus urticae are grown under different photoperiods and the photoperiodic regulation of diapause is examined. The photoperiodic response curve for diapause induction was of the long day,short day type, with critical day lengths (CDLs) of 2 and 12.5 h; diapause was induced between these CDLs. The preimaginal period is significantly longer in diapausing females than in non-diapausing females; moreover, a significant positive correlation is detected between diapause incidence and deutonymphal period. Diapause incidence is high when long-night photoperiods are applied against a background of continuous darkness in the stages including the deutonymph; this stage appears to be the most sensitive to photoperiod. These observations suggest that diapause-inducing conditions inhibit nymphal development, particularly in the deutonymphal stage when photoperiodic time measurement for determination of reproduction or diapause is carried out. [source]


    Phytochromes A1 and B1 have distinct functions in the photoperiodic control of flowering in the obligate long-day plant Nicotiana sylvestris

    PLANT CELL & ENVIRONMENT, Issue 9 2006
    ZHI-LIANG ZHENG
    ABSTRACT The obligate long-day plant Nicotiana sylvestris with a nominal critical day length of 12 h was used to dissect the roles of two major phytochromes (phyA1 and phyB1) in the photoperiodic control of flowering using transgenic plants under-expressing PHYA1 (SUA2), over-expressing PHYB1 (SOB36), or cosuppressing the PHYB1 gene (SCB35). When tungsten filament lamps were used to extend an 8 h main photoperiod, SCB35 and SOB36 flowered earlier and later, respectively, than wild-type plants, while flowering was greatly delayed in SUA2. These results are consistent with those obtained with other long-day plants in that phyB has a negative role in the control of flowering, while phyA is required for sensing day-length extensions. However, evidence was obtained for a positive role for PHYB1 in the control of flowering. Firstly, transgenic plants under-expressing both PHYA1 and PHYB1 exhibited extreme insensitivity to day-length extensions. Secondly, flowering in SCB35 was completely repressed under 8 h extensions with far-red-deficient light from fluorescent lamps. This indicates that the dual requirement for both far-red and red for maximum floral induction is mediated by an interaction between phyA1 and phyB1. In addition, a diurnal periodicity to the sensitivity of both negative and positive light signals was observed. This is consistent with existing models in which photoperiodic time measurement is not based on the actual measurement of the duration of either the light or dark period, but rather the coincidence of endogenous rhythms of sensitivity , both positive and negative , and the presence of light cues. [source]


    NMR-Solution Structures and Affinities for the Human Somatostatin G-Protein-Coupled Receptors hsst1,5 of CF3 Derivatives of Sandostatin® (Octreotide)

    HELVETICA CHIMICA ACTA, Issue 12 2009
    Dieter Seebach
    Abstract The previously reported (Helv. Chim. Acta2008, 91, 2035) derivatives of octreotide (1) with a (CF3)-Trp substitution, i.e., 3, and with open-chain structures, i.e., 2, 4, and 5, have been tested for their affinities to hsst1,5 receptors and subjected to a detailed NMR analysis. Their affinities vary from 15,nM to 5,,M, as compared to 0.6,nM to 0.8,,M for octreotide itself (Table,1). This decreased bioactivity may have had to be expected for the open-chain compounds 4 and 5; possible reasons for this decrease in the case of CF3 derivative of octreotide, 3, are discussed. NMR Analysis (Tables,2 and 3) provides evidence for increased dynamics of all new derivatives 2,5. The dynamics of the octreotide molecule 1 was analyzed by (natural-abundance) longitudinal 13C-T1 -relaxation time measurements (Table,4), from which the conclusion is drawn that the backbone of the macrocycle is rather rigid on the time scale of this method. [source]


    Routine clinical brain MRI sequences for use at 3.0 Tesla

    JOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 1 2005
    Hanzhang Lu PhD
    Abstract Purpose To establish image parameters for some routine clinical brain MRI pulse sequences at 3.0 T with the goal of maintaining, as much as possible, the well-characterized 1.5-T image contrast characteristics for daily clinical diagnosis, while benefiting from the increased signal to noise at higher field. Materials and Methods A total of 10 healthy subjects were scanned on 1.5-T and 3.0-T systems for T1 and T2 relaxation time measurements of major gray and white matter structures. The relaxation times were subsequently used to determine 3.0-T acquisition parameters for spin-echo (SE), T1 -weighted, fast spin echo (FSE) or turbo spin echo (TSE), T2 -weighted, and fluid-attenuated inversion recovery (FLAIR) pulse sequences that give image characteristics comparable to 1.5 T, to facilitate routine clinical diagnostics. Application of the routine clinical sequences was performed in 10 subjects, five normal subjects and five patients with various pathologies. Results T1 and T2 relaxation times were, respectively, 14% to 30% longer and 12% to 19% shorter at 3.0 T when compared to the values at 1.5 T, depending on the region evaluated. When using appropriate parameters, routine clinical images acquired at 3.0 T showed similar image characteristics to those obtained at 1.5 T, but with higher signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR), which can be used to reduce the number of averages and scan times. Recommended imaging parameters for these sequences are provided. Conclusion When parameters are adjusted for changes in relaxation rates, routine clinical scans at 3.0 T can provide similar image appearance as 1.5 T, but with superior image quality and/or increased speed. J. Magn. Reson. Imaging 2005;22:13,22. © 2005 Wiley-Liss, Inc. [source]


    Method for quantitative imaging of the macromolecular 1H fraction in tissues

    MAGNETIC RESONANCE IN MEDICINE, Issue 5 2003
    Stefan Ropele
    Abstract A new method was developed for mapping the relative density of the macromolecular protons involved in magnetization transfer (MT). This method employs a stimulated echo preparation scheme in order to modulate the phase distribution within a spin ensemble. This labeled spin ensemble is then used as an intrinsic indicator, which is diluted due to magnetization exchange with macromolecular protons. A pulse sequence is presented which compensates for longitudinal relaxation, allows observation of the dilution effect only, and provides for calculation of parameter maps using indicator dilution theory. Compared to other quantitative MT techniques, neither additional relaxation time measurements nor knowledge regarding the lineshape of the macromolecular proton pool are required. Moreover, the inherent low specific absorption rate and the low sensitivity for B1 errors make this method favorable in a clinical setting. This sequence was used to measure the macromolecular proton density in cross-linked bovine serum albumin. Using a navigated echo planar readout, the sequence was also employed to visualize the macromolecular content of human brain in vivo. Magn Reson Med 49:864,871, 2003. © 2003 Wiley-Liss, Inc. [source]


    Ergonomic exposure case studies in Massachusetts fishing vessels

    AMERICAN JOURNAL OF INDUSTRIAL MEDICINE, Issue S2 2002
    Scott Fulmer MS
    Abstract Background Musculoskeletal disorders may not have been studied as much as greater risks in the dangerous environment of commercial fishing. Primary prevention of risk for these kinds of injuries and illnesses begins by a detailed understanding of what risks are likely to be common in the different fisheries, and how those risks might be reduced. Methods Ergonomic job analyses were conducted on three different types of fishing vessels in Massachusetts: gillnetting, otter trawling, and lobstering. Direct observation was used to link posture to task. Noise measurements, tool analysis, and cycle time measurements were also included. Results Production speed, materials handling, and vessel movement contributed to musculoskeletal stress by affecting observable postural deviation, repetition, and forceful exertions. Conclusions Interventions to reduce ergonomic risk factors might be possible through utilization of below deck space in certain boats, through better technology, or through simple tool adjustments. Am. J. Ind. Med. Suppl. 2:10,18, 2002. © 2002 Wiley-Liss, Inc. [source]


    Measurement of sliding velocity and induction time of a single micro-bubble under an inclined collector surface

    THE CANADIAN JOURNAL OF CHEMICAL ENGINEERING, Issue 6 2008
    Aref Seyyed Najafi
    Abstract In this study, interactions between a gas bubble and a flat solid surface were investigated by determining two dynamic parameters, bubble sliding velocity underneath an inclined solid surface and induction time of the gas bubble attaching to the solid surface in aqueous solutions. A single micro-bubble was allowed to move vertically toward an inclined solid surface. After reaching its terminal velocity, the bubble approaches the inclined solid surface and slides underneath it. Complete trajectory of the bubble movement was monitored and recorded by a high-speed CCD video imaging system. Various types of gas bubbles (CO2, air, H2, and O2) and solid surfaces such as bitumen-coated Teflon, hydrophobized and hydrophilic silica were used in sliding velocity and induction time measurements. The effect of water chemistry (industrial process water and de-ionized water) and surface heterogeneity on bubble sliding velocity and induction time was investigated. The results showed that the sliding velocity of micro-bubbles under an inclined solid surface is a strong function of water chemistry, gas type, temperature and hydrophobicity of the solid surface. This study provides relevant information on bubble,solid interactions that would assist in the understanding of bubble,solid attachment under diverse conditions. Dans cette étude, on a étudié les interactions entre une bulle de gaz et une surface solide plane en déterminant deux paramètres dynamiques, la vitesse de glissement de bulle sous une surface de solides inclinée ainsi que le temps d'induction de l'attachement d'une bulle de gaz à une surface solide en solution aqueuse. On a fait se déplacer une micro-bulle unique verticalement vers une surface solide inclinée. Après avoir atteint sa vitesse terminale, la bulle s'approche de la surface solide inclinée et glisse sous elle. La trajectoire complète de la bulle a été enregistrée par un système d'imagerie vidéo CCD à haute vitesse. Différents types de bulles de gaz (CO2, air, H2, et O2) et de surfaces solides telles que du téflon enduit de bitume, de la silice hydrophobe et hydrophile, ont été utilisés dans les mesures de vitesse de glissement et de temps d'induction. L'effet de la chimie de l'eau (eau de procédés industriels et eau déminéralisée) et de l'hétérogénéité de la surface sur la vitesse de glissement et le temps d'induction a été étudié. Les résultats montrent que la vitesse de glissement des micro-bulles sous une surface solide inclinée dépend fortement de la chimie de l'eau, du type de gaz, de la température et de l'hydrophobicité de la surface solide. Cette étude fournit des informations pertinentes sur les interactions bulles-solides pouvant permettre de comprendre l'attachement bulles-solides dans des conditions diverses. [source]


    Mixing Time in a Short Bubble Column

    THE CANADIAN JOURNAL OF CHEMICAL ENGINEERING, Issue 2 2003
    M Ravinath
    Abstract Mixing time measurements have been carried out in a 0.2m I.D. short bubble column (Hc/D , 5) with different spargers and for different clear liquid height to diameter (HC/D) ratios. Superficial gas velocity has been varied in the range of 0.01m/s to 0.1m/s. Effect of bulk fluid viscosity on the mixing time has also been studied. The circulation cell model, with two fitted parameters viz. number of circulation cells, S and the inter-cell exchange velocity, Ve, has been used to predict and explain the variation in mixing time and the flow pattern in the short bubble column for different types of spargers. On a effectué des mesures de temps de mélange dans une colonne à bulles courte de 0,2 m de diamètre intérieur (Hc/D , 5) munie de différents aérateurs et pour différents rapports entre la hauteur de liquide clair et le diamètre (HC/D). On a fait varier la vitesse de gaz superficielle dans la gamme de 0,01-0,1 m/s. L'effet de la viscosité en masse du fluide sur le temps de mélange est également étudié. On a utilisé le modèle de zones de circulation, comprenant deux paramètres calés, à savoir le nombre de zones de circulation, S, et la vitesse d'échange entre les zones, Ve, pour prédire et expliquer la variation du temps de mélange et le profil d'écoulement dans la colonne à bulles courte pour différents types d'aérateurs. [source]


    Visible and invisible effects of hurricanes on forest ecosystems: an international review

    AUSTRAL ECOLOGY, Issue 4 2008
    A. E. LUGO
    Abstract Hurricanes have visible and invisible effects on forests. The visible effects are dramatic, noticeable over the short-term and relatively well documented in the literature. Invisible effects are less understood as they require well-focused research both in the short- and long-term time scales. This review of the literature on hurricane effects focuses on the Neotropics and the temperate zone of North America. The material is organized according to a heuristic model that distinguishes between immediate effects (0 to 3 years), immediate responses (0 to 20 years), trajectories of responses (0 to 100 years) and long-term legacies (>100 years). It is suggested that the ecological role of hurricanes involves six principal effects: 1. they change the ecological space available to organisms; 2. they set organisms in motion; 3. they increase the heterogeneity of the landscape and the variability in ecosystem processes; 4. they rejuvenate the landscape and its ecosystems and redirect succession; 5. they shape forest structure, influence their species composition and diversity and regulate their function; and 6. they induce evolutionary change through natural selection and ecological creativity through self-organization. A new approach to hurricane research will study hurricanes at the same scale at which they operate (i.e., across latitudes and longitudes and over disturbed and undisturbed landscapes). This research will require networks of observation platforms located along expected hurricane paths to facilitate forest structure and functioning observations across gradients of hurricane frequency and intensity. This research will also require use of remote sensing and automated wireless technology, hardened to survive hurricane-strength winds and floods to assure real time measurements of the characteristics of hurricanes and ecosystem responses. No progress will be forthcoming in the understanding of hurricane effects if we do not learn to quantify objectively the energy dissipation of hurricanes on the full grid of affected forests as the hurricane passes over a landscape. [source]


    Reproducibility and variability of activated clotting time measurements in the cardiac catheterization laboratory

    CATHETERIZATION AND CARDIOVASCULAR INTERVENTIONS, Issue 3 2005
    Terence M. Doherty
    Abstract The objective of this study was to characterize the reproducibility and variability in the measurement to the activated clotting time (ACT) when performed on two different types of instruments, the HemoTec ACT (Medtronic) and the Hemochron 801 (International Technidyne). The ACT has evolved into the most common point-of-care test used in the cardiac catheterization lab to manage patient heparinization. Since the test has not been standardized, different systems frequently produce different results under the same clinical conditions. Duplicate paired ACT tests (n = 885) from 359 patients were performed on both instruments. Prothrombin times (PT) and activated partial thromboplastin times (aPTT) were also determined on subsets of these same samples (PT = 533; aPTT = 487). The performance and relationships between the two tests were determined using a variety of statistical analytical techniques. The average difference between the ACT devices was only 8 sec, yet more than 60% of the measurements varied by more than 10%. Over one-fourth of measurements varied by more than 20%. The reproducibility to the HemoTec instrument was superior to the Hemochron instrument across the entire range of ACTs measured (mean coefficient of variation 2.4% 54± 3.1% vs. 7.2% 54± 6.1% for HemoTec and Hemochron, respectively; P < 0.00001; range = 65,555 sec). The relationship between the two ACTs was nonlinear. In therapeutic ranges used for interventional procedures (200,350 sec), HemoTec and Hemochron ACTs are not comparable to one another. Statistical comparative analysis indicated that the HemoTec ACT has better overall performance. © 2005 Wiley-Liss, Inc. [source]


    Probing the Local Structure of Pure Ionic Liquid Salts with Solid- and Liquid-State NMR,

    CHEMPHYSCHEM, Issue 1 2010
    Peter G. Gordon
    Abstract Room-temperature ionic liquids (RTILs) are gaining increasing interest and are considered part of the green chemistry paradigm due to their negligible vapour pressure and ease of recycling. Evidence of liquid-state order, observed by IR and Raman spectroscopy, diffraction studies, and simulated by ab initio methods, has been reported in the literature. Here, quadrupolar nuclei are used as NMR probes to extract information about the solid and possible residual order in the liquid state of RTILs. To this end, the anisotropic nature and field dependence of quadrupolar and chemical shift interactions are exploited. Relaxation time measurements and a search for residual second-order quadrupolar coupling were employed to investigate the molecular motions present in the liquid state and infer what kind of order is present. The results obtained indicate that on a timescale of ,10,8 sec or longer, RTILs behave as isotropic liquids without residual order. [source]


    Highly Durable Ceramic Thermometer for Molten Metal

    INTERNATIONAL JOURNAL OF APPLIED CERAMIC TECHNOLOGY, Issue 1 2006
    Hideki Kita
    It was shown that a silicon nitride (SN)/boron nitride (BN) composite laminate provides excellent thermal shock resistance, and to improve the corrosion resistance of the SN pipe against molten metals, the Mo/ZrB2 film was effective for molten cast iron. The authors have developed a thermocouple that yields high durability and good response using an SN/BN composite laminate as an external sleeve and film-coated SN protection tube. According to the results of repeated temperature measurement tests for molten metals, it was demonstrated that the thermometer thus designed had high durability, e.g., 360 times measurement to life was achieved for molten cast iron. [source]


    Brachial-ankle pulse wave velocity measured automatically by oscillometric method is elevated in diabetic patients with incipient nephropathy

    DIABETIC MEDICINE, Issue 11 2003
    H. Yokoyama
    Abstract Aims To examine whether brachial-ankle pulse wave velocity (baPWV), a possible early marker of atherosclerotic vascular damage, is associated with albuminuria in patients with Type 2 diabetes. Methods BaPWV was measured by automatic oscillometric method in 346 Type 2 diabetic patients with normoalbuminuria (a mean level of three times measurements of albumin-to-creatinine (ACR) < 30 µg/mg creatinine; n = 200), incipient nephropathy (a mean level of ACR , 30 and < 300 µg/mg creatinine; n = 119), and clinical nephropathy (a mean level of ACR , 300 µg/mg creatinine; n = 27), and without peripheral vascular disease. Results BaPWV (cm/s) was significantly higher in patients with incipient nephropathy (1722 ± 382) and clinical nephropathy (1763 ± 322) than in patients with normoalbuminuria (1559 ± 343, P < 0.0001, respectively). By univariate analysis it correlated significantly with age (r = 0.44, P < 0.0001), systolic blood pressure (r = 0.55, P < 0.0001), diastolic blood pressure (r = 0.42, P < 0.0001), albuminuria (r = 0.24, P < 0.0001) and HbA1C (r = 0.11, P < 0.05). Albuminuria revealed an independent significant association with baPWV (P < 0.01) after adjustment for age, sex, smoking, BMI, HbA1C, hyperlipidemia, and hypertension. Multiple regression analysis showed age, diastolic blood pressure and albuminuria were independently associated with baPWV (adjusted R2 = 0.42, P < 0.0001). Conclusions The results might indicate a possible link between the pathogenesis of atherosclerosis and diabetic nephropathy. Future studies are needed to clarify the usefulness and its predictable value. [source]


    Complex 1H,13C-NMR relaxation and computer simulation study of side-chain dynamics in solid polylysine

    BIOPOLYMERS, Issue 3 2005
    Alexey Krushelnitsky
    Abstract The side-chain dynamics of solid polylysine at various hydration levels was studied by means of proton spin,lattice relaxation times measurements in the laboratory and tilted (off-resonance) rotating frames at several temperatures as well as Monte Carlo computer simulations. These data were analyzed together with recently measured carbon relaxation data (A. Krushelnitsky, D. Faizullin, and D. Reichert, Biopolymers, 2004, Vol. 73, pp. 1,15). The analysis of the whole set of data performed within the frame of the model-free approach led us to a conclusion about three types of the side-chain motion. The first motion consists of low amplitude rotations of dihedral angles of polylysine side chains on the nanosecond timescale. The second motion is cis,trans conformational transitions of the side chains with correlation times in the microsecond range for dry polylysine. The third motion is a diffusion of dilating defects described in (W. Nusser, R. Kimmich, and F. Winter, Journal of Physical Chemistry, 1988, Vol. 92, pp. 6808,6814). This diffusion causes almost no reorientation of chemical bonds but leads to a sliding motion of side chains with respect to each other in the nanosecond timescale. This work evidently demonstrates the advantages of the simultaneous quantitative analysis of data obtained from different experiments within the frame of the same mathematical formalism, providing for the detailed description of the nature and geometry of the internal molecular dynamics. © 2005 Wiley Periodicals, Inc. Biopolymers 78: 129,139, 2005 This article was originally published online as an accepted preprint. The "Published Online" date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com [source]